Non ASCII email formating

Question

When I'm trying to send a mail with a unicode char like this fòò@bar.com
the To was changed to something like this: xn--f-tgaa@bar.com
Precedent version change nothing.
What was changed and why ?

Our server doesn't support Unicode.
Last version throw an exception on Send when the new one send without any probleme and got DSN return.

The last version before we decided to update was 3.0.16219.2132

We want to understand what happen now, and why did it change.

Thank you

Answer 1

xn--f-tgaa@bar.com email address is using punycode to represent UTF8 characters in email address.

It is used when the sending SMTP server doesn't support UTF8 and message uses UTF8 email address/domain.

If you don't want to send emails to UTF8 addresses, you'll need to validate and reject non-ASCII recipient addresses before sending.